Cervical lymph node metastases of squamous cell carcinoma from an unknown primary site

Abstract

Cancer of unknown primary (CUP) is a well-recognized clinical disorder where the primary site cannot be identified after a standard diagnostic approach and it accounts for 3-5 % of all tumors. CUP is distinguished into two different clinicopathological entities, favorable or unfavorable. The subset of squamous cell carcinoma metastatic to cervical lymph nodes constitutes the 5 % of all head-and-neck cancers. For detection of the primary site, all patients need a detailed clinical examination and imaging investigation including PET scans, panendoscopy with directed biopsies, and possibly bilateral tonsillectomy. Lymph nodal stage, extracapsular spread, and HPV status are considered as the most prominent prognostic factors. Although, randomized trials are lacking concerning the optimal therapeutic management, combined-modality treatment is offering the most encouraging results. Surgery alone is indicated in N1 or N2a stages. Radiotherapy is used as a single modality for early-stage pN1 without extracapsular extensions or combined with neck dissection as postoperative therapy in more advanced disease. Chemoradiation can also be given in a neoadjuvant setting followed by surgery in certain cases as well in patients with comorbidities. Prognosis in general is encouraging with 5-year progression-free and overall survival rates of 85% and 75%, respectively. © Springer International Publishing Switzerland 2011, 2016.